1. Field of the Invention
This invention relates to a forming system for forming glass, more particularly to a continuous forming system for producing optical lenses.
2. Description of the Related Art
Referring to FIG. 1, a typical forming system for producing optical glasses, includes a forming room 1, a first standby zone 2 adjacent to an entrance of the forming room 1, two successive heating zones 3 disposed in the forming room 1 adjacent to the first standby zone 2, two successive forming zones 4 disposed in the forming room 1 adjacent to the heating zones 3, three successive cooling zones 5 disposed in the forming room 1 adjacent to the forming zones 4, a second standby zone 6 disposed adjacent to an exit of the forming room 1 immediately downstream of the cooling zones 5, a third standby zone 7 downstream of the second standby zone 6, a separation zone 8 downstream of the third standby zone 7, a replacement zone 9 downstream of the separation zone 8, an assembly zone 101 downstream of the replacement zone 9, a fourth standby zone 102 disposed between the first standby zone 2 and the assembly zone 101, a suction nozzle 103 disposed adjacent to the replacement zone 9 for sucking lens or glass blanks, and fourteen sets of forming units 104 disposed respectively in the aforesaid zones. Each forming unit 104 includes a sleeve member 1041, a lower molding core 1042 disposed in the sleeve member 1041 for holding a glass blank 105, and an upper molding core 1043 movably disposed in the sleeve member 1041 above the lower molding core 1042.
When a continuous production operation of lenses starts in the forming system, the forming units 104 together with glass blanks 105 thereon are moved successively from the first standby zone 2 to the heating zones 3 to soften the glass blanks 105. Thereafter, the forming units 104 are moved one after the other to the forming zones 4 for press-forming the glass blanks 105 into lenses 106, and further to the cooling zones 5 to cool down the lenses 106. Afterwards, the forming units 104 together with the lenses 106 are moved successively to the second standby zone 6 where the forming units 104 are picked up by a robot arm (not shown) one after the other to the third standby zone 7. The forming units 104 with the lenses 106 are then moved to the separation zone 8 at which each upper molding core 1043 is separated from the corresponding lower molding core 1042 and from which each lower molding core 1042 with the corresponding sleeve member 1041 is moved to the next replacement zone 9. At this stage, the suction nozzle 103 is moved downward to pick up the lens 106 from each lower molding core 1042 for removal to a storage region (not shown), and then brings a glass blank 105 from another storage region to each lower molding core 1042. Each glass blank 105 is then brought by the corresponding lower molding core 1042 and sleeve member 1041 to the assembly zone 101 where a robot arm (not shown) is used to assemble each lower molding core 1042 with another upper molding core 1043. Finally, each forming unit 104 together with the glass blank 105 is moved to the fourth standby zone 102 and then resent to the first standby zone 2 for continuous operation.
In the aforesaid forming system, since separation and assembly of each forming unit 104 are carried out separately at two different zones, i.e. the separation and assembly zones 8 and 101, additional operation steps are necessary to transfer the forming units 104 between the two zones, thus increasing the complexity of the operation and the construction of the system and adversely affecting the production rate. In addition, the need to perform aligning and positioning of the components of each forming unit 104 in each of the two zones also complicates the forming system.
Furthermore, it is difficult to center the glass blank 105 with respective to the central axis of the sleeve member 1041 of the forming unit 104 so that the glass blank 105 is vulnerable to positional deviation when being transferred to the replacement zone 9, or to the assembly zone 101 from the replacement zone 9. The positional deviation can result in defective products with asymmetric thickness.